Things about mobile devices that I've learned while having to use them with one hand while my infant son sleeps cradled on my other arm:
1. Typing out emails with one thumb is tedious. Spellcheck is overzealous and honestly requires more retyping than it saves.
2. Among mobile devices, the Kindle (I use a 3rd gen) has far and away best combination of weight and size for the single-handed user. On +Ted Rheingold
's suggestion I've been reading "Brain Rules for Baby," which is utterly fascinating/fantastic.
3. Both the iPad and iPad 2 are still both too heavy to use with one hand over a lengthy period of time. Gestures suck when you have to put the device down to make the simplest thing happen (e.g. "next page" - thanks, Kindle!)
4. An open laptop on the couch beside you, with one hand free to hunt, peck and mouse around still tops most other devices for sheer functionality and ease of use. Which I think is kind of sad.